Three elements of moisture-proof packing for products package: the desiccant, humidity indicator card and Aluminum foil bag.
According to the requirements of moisture-proof grade of packaging products, three moisture-proof packaging products, namely desiccant humidity card moisture-proof bag, are indispensable in SMD packaging with moisture-proof grade of 2-5A.
Aluminum foil bag is used for packaging products, isolated from the outside water vapor into the bag, to avoid the products in the bag contact the outside humid air. Moisture-proof bag should comply with MIL-PRF -81705 standard type I requirements, including its toughness, anti-static performance, anti-puncture performance, and barrier performance. Water vapor permeability shall be less than or equal to 0.031g/㎡(0.002g/100in²) within 24 hours at 40℃. Water vapor permeability shall be measured by ASTM F1249.
Desiccant is used to absorb moisture in the bag after packaging, it should be dust-free, non-corrosive, and up to the standard of water absorption. The field life of the desiccant is limited. After opening the package, it should be put into the moisture-proof bag as soon as possible. After the humidity card is next to the moisture-proof bag, it should be vacuumized as soon as possible. The effect of absorbing moisture will be decreased if the desiccant exposed in the air for a long time even after vacuumized.
U.S. military standards define the amount of desiccant a UNIT can absorb at least 2.85 grams of water at a temperature of 25 ° C and a humidity of 20%.
Humidity card is used to indicate the humidity in the bag. The color spot indicates humidity by a distinct, easily recognizable color changed. Indicator scale 5%-10%-60% blue to pink. 5%, 10% of the color spots on the HIC should be reversible and reusable. But the HIC cannot be reused when 60% of the dots change color from blue to pink.
Attention:
Desiccant and humidity indicator cards are sensitive to humidity, it should be placed in dry and cool environment, avoid direct sunlight and water. Unused products need to be sealed well. Shelf life of desiccant: 12 months (sealed preservation).
Keep the humidity indicator cards sealed in the original packaging tin and put in a desiccant. Replacing the desiccant after opening the tin for three times. Storage life: about 6 months.
After opening the small package of humidity card, it must be used up within 30 minutes. Humidity card is a sensitive product to touch humidity. When exposed to the air for too long, the potion will react and change color.
The aluminum foil bag needs special attention to scratch or foreign material, which will destroy the aluminum foil layer of the bag. Once damaged, it is easy to leak after vacuuming.